Process of mounting and soldering electrical filaments.



i U m i Z i I S. MARIETTI.

PROCESS OF MOUNTING AND SOLUERING ELECTRICAL PILAMBNTS.

APPLICATION FILED JULY 2, 1908.

1,029,383, Patented June 11, 1912.

COLUMBIA PLANOGRAFH CO.,WASHINGTON, D c.

UNITED STATES PATENT OFFICE.

SILVIO MARIET'II, 0F ALPIGNANO, NEAR TURIN, ITALY, ASSIGNOR TO SOCIETE ANO- NYlVIE DES PERFECTIONNEMENTS ,AUX LAIVIPES ELECTRIQUES A FILA1VIENTS METALLIQUES, OF BRUSSELS, BELGIUM.

PROCESS OF MOUNTING AND SOLDERING ELECTRICAL FILAMENTS.

To all whom it may concern:

Be it known that I, SILVIO MARIETTI, a subject of the King of Italy, and resident of Alpignano, near Turin, Italy, have invented certain new and useful Improvements in Processes of Mounting and Soldering Electrical Filaments, of which the following is a specification.

The object of the present invention is to devise a process for rapidly mounting and soldering to their carriers the metallic filaments used in incandescent electric lamps, and to conduct such process in the free air in such a manner that oxidation of the filament is prevented.

The practice of my invention is adapted to the use of nickel wires, of a tubular shape as filament carriers, and similar to those employed for supporting the carbon filaments in ordinary incandescent electric lamps.

The practice of my process may be effected by the use of the apparatus shown in the accompanying drawing, in which Figure 1 represents, in side elevation, a nickel wire holder having a tubular end for engaging the refractory metallic filament, similar to those used in ordinary carbon incandescent electric lamps. Fig. 2 represents, in side elevation, such nickel wire holder after it has been bent according to the requirements of the present invention. Fig. 3 represents, diagrammatically, one method of mounting the filaments in an incandescent electric lamp. Fig. 4 is a similar view of another method of mounting the filaments.

Referring to Fig. 1, a nickel wire carrier having a tubular end a for engaging a metallic filament is here represented, which, as shown in Fig. 2, is bent so that the tubular port-ion is disposed at an angle of about 90 to the wire portion, and is, according to the present invention, in the proper position for receiving the metallic filament through the opening 0. A suitable lamp carrier may be employed, according to whether the filaments have a pointed form as shown in Fig. 3, or are horse-shoe or U-shaped as shown in Fig. 4. The filaments will be mounted in this manner, that one end of the filament will be placed in the tubular end of one of the filament carriers, and then the filament Specification of Letters Patent. v

Application filed July 2, 1908.

is bent so that either a sharp point is pro- Patented June 11, 1912.

Serial No. 441,624.

duced, as shown in Fig. 3, or it is bent so that part of its length conforms approximately to the arc of a circle, as shown in Fig. 4; the other end of the filament will be placed in the tubular end of the next filament carrier. This operation can be easily and rapidly executed, as the tubular ends of the nickel wires bent in the manner described are especially adapted to receive the filaments and to support them with the aid of hooks.

In the embodiment of my invention shown in Fig. 3, the tubular portion 25 receives the ends of two adjacent filaments, this system being suitable for use in connection with pointed filaments as here represented.

Fig. 4 represents a method of mounting the filaments, according to which, the two adjacent filaments are introduced into two separate tubes 25, If, this structure being suitable for the horse-shoe shaped filaments.

After the filaments are mounted in the manner described, they may be secured to their corresponding carriers by the application of a suitable paste or cement at the part 0 (shown in Fig. 2) into which the filament f has been introduced. A cement containing the metal of which the filament is made may be used, but I wish it to be understood that this application of the paste or cement is not absolutely necessary, as it has for its object merely to render the soldering operation, which will presently be described, more rapid.

According to my invention, the autogeneous soldering of the filaments will be carried out by means of the voltaic acid. In the drawing I have represented two poles of a suitable electric circuit, to which the positive and negative signs of polarity are applied. In performing the soldering operation, I connect one of the nickel filament carriers at a suitable point with one of the poles of the circuit, while, by applying the pole of opposite polarity to or near the end of the tubular part of the carrier (shown in Figs. 3 and 4:) an arc will be drawn from the end 7'. As a resulting effect of the high temperature of the arc so produced, the nickel of the tubular part a of the wire carrier will assume the molten condition and will become soldered to the filament which it engages, but only a sufiicient portion of the tubular carrier and of the filament within the tubular carrier will assume the molten state as to effect a good soldering, and as the operation can be effected very rapidly, the portion of the filament just above the tubular carrier is not heated to incandescence. If this operation were carried out in the free air under ordinary conditions and without the special provision which forms an important step of my process, that portion of the filament at or near the soldering point would be strongly oxidized and might be destroyed as a result of such oxidizing action. According to the present invention, however, I prevent oxidation of the filament almost completely by causing an air current to act upon the point Where the electric arc is produced. I preferably apply such air current to the soldering point by passing it in a direction about opposite to that of the electric current as it flows through the filament, and in a direction approximately at a right angle to the position of the poles of the electric circuit, as shown in Figs. 3 and 4. In the said figures, I have represented a tube 8 for applying the air current, and have indicated by an arrow the direction of fiow of the air. The filament during the soldering process is not rendered incandescent outside of Where it engages the tubular ends of the nickel Wire carriers, and it therefore does not oxidize, the only part of the filament which would otherwise oxidize being protected by the tubular carriers. The tubular carriers, as it were, form a protecting envelop agains oxidation of the filament at the only points where the filament is made incandescent. As the heated air is carried in a direction downwardly from the tubular carriers, none can therefore act to oxidize the filaments above the tubular carriers. By varying the pressure of the air which is directed in such current at the region of the soldering operation, I may control the intensity of the spark, in case a too rapid fusion of the nickel is obtained.

I claim 1. The improvement in the art of connecting a lamp filament to a leading-in-conductor, which consists in producing an arc at the junction of the filament and conductor, and simultaneously directing a current of air on the region of formation of the arc, thereby deflecting the latter away from the leg of the filament.

2. The improvement in the art of connecting a lamp filament to a leading-in-conductor, which consists in protecting a portion of the filament by a portion of the conductor and producin an arc at such protected portion of the filament, whereby the filament will become soldered to the conductor at such protected portion, and simultaneously directing a current of air on the region of formation of the arc, thereby deflecting the latter away from the leg of the filament.

3. The improvement in the art of connecting a lamp filament to a leading-in-conductor, which consists in protecting a portion of the filament by a portion of the conductor, passing an electric current through the conductor and producing an are at such protected portion of the filament, whereby the filament will become soldered to the conductor at such protected portion, and simultaneously directing a current of air on the region of formation of the arc, thereby defiecting the latter away from the leg of the filament.

In testimony whereof I have hereunto set my hand in presence of two witnesses.

SILVIO MARIETTI.

lVit-nesses QUARTIo GIUSEPPE, LOUIS ALLAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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